A polypropylene resin composition comprises (1) 40 to 99% by weight of a polypropylene resin; (2) 1 to 60% by weight of an ethylene/alpha-olefin copolymer elastomer; (3) 20 to 50 parts by weight of a low molecular weight polypropylene resin modified with unsaturated carboxylic acid or its anhydride, and (4) 0.1 to 20 parts by weight of an epoxy resin represented by the following chemical formula I: ##STR1## wherein n is an integer of 1 to 4 and A is a multivalent group having a bond number of n and is selected from bisphenol A-type ethers, propylene oxide-type ethers and ethylene oxide-type ethers, the components (3) and (4) being based on 100 parts by weight of the components (1) and (2) in total. The composition is suited for polypropylene materials to be painted, such as automobile bumpers, by virtue of its superior paint adhesion even under the condition of no pretreatments.